Dental Research Journal
Volume:18 Issue: 7, Aug 2021

Only a few controversial studies have assessed the repair bond strength of a fresh composite to aged composite. Moreover, no studies exist on repair bond strength of fresh composites to bleached composites. Therefore, this preliminary study was conducted to assess repair shear bond strength (SBS) of three composites bonded to nonbleached and at‑home and in‑office bleached composites.

In this experimental in vitro study, 108 disks(36 specimens per composite) of hybrid, microhybrid, and nanofilled composites were divided into three subgroups of three bleaching treatments: no bleaching (control), at‑home bleaching, and in‑office bleaching. Composite disks were incubated for 4 weeks in artificial saliva (also dipped in tea and coffee for 3 h a day). They were then thermocycled (5000 cycles). Afterward, the control group remained unbleached, while the other groups were bleached according to office and home bleaching methods. They were repaired with the same composite type. Their repair SBS and mode of failure were measured and analyzed using two‑way ANOVA, Tukey, one‑sample t‑test, and Chi‑square tests (α = 0.05, β = 0.2).

The mean (standard deviation) SBS values of hybrid, microhybrid, and nanofilled composites were 20.71 ± 5.99, 21.06 ± 6.68, and 9.46 ± 4.32 MPa, respectively. The mean SBS values of the bleaching techniques “home bleaching, office bleaching, and no bleaching (control)” were, respectively, 16.35 ± 7.13, 16.39 ± 8.07, and 18.49 ± 8.35 MPa. There was a significant difference among composites (two‑way ANOVA P = 0.000) but not among nonbleaching/bleaching methods (P = 0.176). Their interaction was significant (P = 0.017). The difference between hybrid and microhybrid was not significant. Nevertheless, nanofilled had significantly poorer results compared to both hybrid and microhybrid composites (Tukey P = 0.000). Both hybrid and microhybrid were capable of producing satisfactory clinical repair bond strengths (above 20 MPa) regardless of bleaching or lack of it. Nanofilled composite failed to provide proper repair SBS values, even in the control (no‑bleaching) group. By moving from Z100 or from Z250 to Z350, modes of failure shifted from mostly cohesive to mostly adhesive (P < 0.05).

Bleaching of an aged composite might not affect the repair bond strength. Hybrid and microhybrid composites can provide clinically acceptable repair bond strengths, regardless of bleaching. Nonetheless, nanofilled composite is inferior to them and cannot provide appropriate repair bond strengths (regardless of bleaching).

The purpose of this study was to evaluate the effect of Vitamin E supplements on chronic periodontitis based on the clinical parameters of pocket depth and clinical attachment level and total antioxidant capacity (TAC) of saliva.

In this clinical trial, 16 patients with chronic periodontitis were selected and divided into two groups. The indices of pocket depth and attachment loss for 6 teeth per person were measured with a periodontal probe. A total of 41 teeth in the control group and 42 teeth in the case group were examined. Then, 2 ml nonstimulated saliva was collected from each patient. All patients were treated with scaling and root planing (SRP). The case group consumed 200 IU supplementary Vitamin E daily for up to 2 months. After 2 months, clinical indices were re‑measured and 2 ml nonstimulated saliva was collected. The TAC of saliva samples was measured by using Zellbio’s TAC Kit. Data were analyzed by the SPSS software and were evaluated in each group between the first session and 2 months later with paired t‑test. The differences between the two groups were evaluated through the independent t‑test (α ≤ 0.05).

Independent t‑test showed that mean change in TAC (P = 0.14) and pocket depth changes (P = 0.33) was not significant between two groups 2 months after SRP, but mean attachment loss changes in the case group was significantly less than the control group (P = 0.03).

The results of this study indicate that Vitamin E supplementation with SRP can reduce the inflammatory process of periodontitis and improve periodontal clinical indices and decrease the amount of attachment loss.

Nitric oxide (NO) has several functions in bone healing and affects bone metabolism. Selective inducible NO synthase (iNOS) inhibitors can be used to assess the efficacy of NO for healing of bone defects. This study sought to assess the local effect of different concentrations of aminoguanidine hydrochloride (AG), a selective iNOS inhibitor, on bone healing in rats.

In this animal experimental study, 72 rats were divided into six groups of control, placebo, 5% AG, 10% AG, 15% AG, and 20% AG. A bone defect measuring 5 mm × 5 mm was created in the femur. The defect remained empty in the control group. In the placebo group, neutral gel was placed in the bone defect, and in the remaining four AG groups, different concentrations of AG were applied to the defects. Bone healing was assessed histologically. The healing score in the six groups was analyzed by the Kruskal–Wallis test. A P < 0.05 was considered statistically significant.

The healing score in 20%, 15%, 10%, and 5% AG groups was significantly higher than that in the neutral gel and control groups (P < 0.01). Among the four groups of AG, 20% concentration showed better results, but the difference was not significant.

Four concentrations of AG caused greater bone healing compared to the other two groups. Selective iNOS inhibitors such as AG can be used to promote local bone healing.

The purpose of this in vitro study was to evaluate the effect of five different surface treatments on the mechanical property and antimicrobial effect of three desiccated glass ionomer cements.

In this in vitro experimental study, 300 rectangular blocks of three different restorative materials were fabricated using an aluminum mold, Group I (n = 100) Micron bioactive, Group II (n = 100) GC Fuji IX GP Extra, and Group III (n = 100) bioglass R. These blocks were stored in 100% humidity for 24 h and then placed in air to desiccate for another 24 h. These groups were further divided into two major groups (n = 50) for both mechanical (Flexural) and antimicrobial testing. The blocks of mechanical and antimicrobial groups were further divided into five subgroups (n = 10) based on the medias used for surface treatment (senquelNaF, MI varnish, chlorhex plus, kedodent mouthwash, and 100% humidity [control]). Flexural strength (FS) was measured using the universal testing machine. Fracture strength of groups was compared using the one‑way analysis of variance and Tukey’s post hoc test with P ≤ 0.05 considered statistically significant. Antimicrobial effect was carried out by covering the specimens in a suspension of Streptococcus mutans followed by incubation for 24 h. The blocks were later washed, vortex mixed, serially diluted, and plated. Ccolony‑forming unit/ml was calculated after 3 days of incubation. Data were then analyzed using the Kruskal–Wallis and Mann–Whitney U nonparametric test, with P ≤ 0.05 considered statistically significant.

Micron bioactive with the surface treatment of MI varnish significantly exhibited highest FS. Surface treatment of desiccated restorative materials with chlorhex plus exhibited no growth of S.mutans. GC Fuji IX GP Extra with surface treatment of MI varnish exhibited highest reduction in S. mutans growth compared to other experimental group.

Surface treatment of restorative material with MI varnish improved their mechanical and antimicrobial property while among three restorative materials Micron bioactive showed better mechanical property, whereas GC Fuji IX GP Extra exhibited better antimicrobial property.

To evaluate whether the long‑term use of complete dentures (CD) into promotes significant changes in the oral health‑related quality of life (OHRQoL) in edentulous patients.

A systematic review and meta‑analysis was conducted. A broad search in Pubmed, Web of Science, Scopus, Cochrane Library, Grey Literature, clinical trials registers and manual search was done. The eligibility criteria were based on population, intervention, comparisons and outcome:(P) edentulous patients,(I) CDs rehabilitation,(C) OHRQoL after CD,(O) change in scores of OHRQoL. Two independent reviewers applied the eligibility criteria, collected qualitative data, performed methodological quality and evaluated the certainty of the evidence (grading of recommendations assessment, development and evaluation). The meta‑analysis was analyzed in RevMan 5.4 with 95% confidence intervals (CIs) and P < 0.05.

A total of 2452 records were identified. Twenty‑four articles were included in qualitative synthesis. Nineteen studies were qualified as good, 3 as fair and 2 as poor quality. Twelve studies were included in quantitative analysis(meta‑analysis). The use of CD did not improved OHRQoL in a period of 3 months through the assessment of the Geriatric Oral Health Assessment Index (GOHAI) instrument (P = 0.55; CI; 6.86 [−15.60, 29.31]), and Oral Health Impact Profile‑14 (OHIP‑14) (P = 0.05; CI; −14.91 [−29.87, 0.04]), with very low certainty of evidence. In a long term, 6 months, GOHAI instrument (P < 0.00001; CI; 16.22 [10.70, 21.74]), OHIP 20 (P = 0.02; CI; −11.09 [−20.54, −1.64]) and OHIP-EDENT (P = 0.0004; CI; −8.59 [−13.32, −3.86]) showed improvement on OHRQoL, with very low and low evidence of certainty, respectively.

CD has the strong potential to contribute to oral health‑related quality of life in long‑term.

Interleukin‑29 (IL‑29) is one of the cytokines which has immunomodulatory properties and might play a role in the pathogenesis of periodontal diseases. The aim of this study was an immunohistochemical analysis of IL‑29 in gingival tissues of chronic and aggressive periodontitis.

In this cross‑sectional study based on clinical evaluation and inclusion and exclusion criteria, 20 patients with generalized chronic periodontitis, 13 patients with generalized aggressive periodontitis, and 20 periodontally healthy individuals were enrolled. Gingival tissue samples were obtained during periodontal flap and crown lengthening surgery in periodontal patients and healthy individuals, respectively. Tissue samples were examined to determine the level of IL‑29 expression by immunohistochemistry. The data were analyzed using SPSS and paired t‑test, ANOVA test, and Tukey’s test (P < 0.05).

A total of 53 participants (34 females and 19 males) were enrolled in this study. IL‑29 expression in the connective tissue of the patient groups was more than the healthy one (P < 0.001). In the aggressive periodontitis group, there was a significant increase of IL‑29 expression compared to the other two groups, but there was no significant difference between the chronic periodontitis and healthy groups.

According to the results of this study, IL‑29 expression was increased in the gingival tissue of aggressive and chronic periodontitis. IL‑29 local expression in aggressive periodontitis is higher than the chronic periodontitis and healthy groups, which could suggest the role of IL‑29 in the etiopathogenesis of aggressive periodontitis.

COVID‑19 outbreak in 2019 took the entire world by a storm with the medical fraternity struggling to understand and comprehend its complex nature. A number of patients who are COVID positive have reported oral lesions. However, there is still a lingering question, whether these lesions are because of coronavirus infection or they are secondary to the patient’s systemic condition. This article aims to report the oral findings of an observational study of 713 patients diagnosed with COVID‑19.

A singlssswe‑institution, short‑term observational study was conducted on patients admitted to Symbiosis University Hospital and Research Centre, Lavale, Pune who were positive to coronavirus, who presented varied oral findings such as herpes simplex, candidiasis, geographic tongue, and aphthous ulcer.

A total of 713 patients, 416 males and 297 females, who were positive to coronavirus, were screened from April 2020 to June 30, 2020, for oral ulcers. In this group, nine patients reported oral discomfort due to varied forms of oral lesions ranging from herpes simplex ulcers to angular cheilitis (1.26%).

This study supports the hypothesis that oral manifestations in patients diagnosed with COVID‑19 could be secondary lesions resulting from local irritants or from the deterioration of systemic health or could be just coexisting conditions. No specific pattern or characteristic oral lesions were noted in a study of 713 COVID‑positive patients in our study to qualify these lesions as oral manifestations of SARS‑CoV‑2 infection.

Presurgical nasoalveolar molding (PNAM) was introduced by Grayson et al., in 1993 to presurgically mold the alveolus, lip, and nose in infants with cleft lip and palate (CLP). The aim of this comparative clinical trial was to evaluate the efficacy and efficiency of Modified and Conventional Grayson’s PNAM in patients concerning morphological and anatomical changes in maxillary alveolus, nasal symmetry, number of visits, and duration of treatment.

In this comparative clinical trial study, 16 infants with unilateral complete CLP were equally divided into two groups: Group I (modified PNAM technique using titanium molybdenum alloy [TMA] wire nasal stent) and Group II (conventional PNAM technique using stainless steel wire nasal stent). Patient photographic evaluation of nasal symmetry and maxillary study model CAD‑CAM analysis, pre‑ and post‑operatively in both groups, were compared using a paired t‑test between the groups using the Chi‑square test with P < 0.05 as statistically significant.

In both groups, on evaluating nasal measurements, statistically significant (P < 0.05) decrease in nasal width and increase in columella deviation angle, a decrease of nostril length, and an increase of columella length in Group I were observed. On maxillary study model evaluation, a statistically significant (P < 0.05) decrease in width of the alveolar cleft was noticed in both groups and lateral deviation of the incisal point in Group I and width of the palatal cleft in Group II was noticed.

This study showed a morphological improvement in nasal symmetry and maxillary alveolar morphology in complete unilateral CLP patients, treated with both Modified and Conventional PNAM techniques, with the Modified PNAM technique being more efficient for treatment duration and the number of adjustments as there are less number of visits.

A bonded fixed retainer is used to stabilize the alignment of the teeth. Different composites have been introduced for this purpose. This study aimed to investigate the wear resistance of flowable nanocomposite in comparison with microhybrid composite in an in vitro situation.

In this in vitro study, 46 disk‑shaped specimens were divided into two groups: Filtek Ultimate flowable composite and Z250 microhybrid composite. The samples were prepared in 8 mm diameter and 3 mm thickness in an aluminum mold and light cured. They were polished with 600 grit sandpaper to achieve a smooth surface. Two‑body wear test was accomplished by the pin‑on‑disk device (under 15 N, 20 rpm for 1 h). Analyzing the weight and thickness of specimens before and after the assay demonstrates the wear resistance. Data were analyzed using the t‑test. P ≤ 0.05 was considered statistically significant.

The Filtek Ultimate flowable composite shows no significant difference compared to Z250 microhybrid composite in thickness (P = 0.701) and weight (P = 0.939) of specimens.

Due to wear resistance of both materials, flowable composite can be recommended as an alternative material for bonded fixed retainers.

Squamous cell carcinoma (SCC) is the most common oral malignancy with high rate of mortality. Cisplatin, as the most effective chemotherapy drug, has side effects. Considering the studies on the use of crocin in saffron in the treatment of various malignancies, this study aimed at investigating the effects of crocin and cisplatin and their combination on SCC and fibroblast cell lines.

In this interventional study, HN5 and fibroblast cell lines were treated with different concentrations of crocin (12.5–50 µg/mL) and cisplatin (2, 4, 8, 16, and 32 µg/mL), and the cells were counted after 24, 48, and 72 h by 3‑(4,5‑dimethylthiazol‑2‑yl)‑2,5‑diphenyltetrazolium bromide assay. Data were analyzed with SPSS Version 17, and P < 0.05 was considered the level of significance. In the final stage, flow cytometry after 24 h in terms of the pattern of cell death was done.

Both drugs had a toxic effect on malignant cells. One point was the high toxic effect of 8 μg/mL cisplatin not only on cancer cells (P < 0.001) but also on fibroblasts. However, combination with 12.5 μg/mL of crocin had the same effect on HN5 cell line, despite the less toxic effect in fibroblasts in comparison with cisplatin alone (P = 0.012). Apoptosis was the pattern of cell death showed by flow cytometry.

Crocin in high concentrations can have not only significant toxicity in cancer cells but also side effects in healthy tissue. It seems that lower doses of crocin, in combination with cisplatin, besides having anticancer effect, can reduce the toxicity of cisplatin in healthy tissue.